More often than not, when I make the Figs In Rum Syrup from How To Be A Domestic Goddess, I end up with a layer of crystallized sugar at the bottom of the jar. I have always followed the recipe as closely as possible. What am I doing wrong? I end up taking the figs out of the jar, adding the syrup and sugar to a pan with quite a bit of extra rum, then slowly bringing to a boil before returning everything to a clean jar. This seems to fix the issue, but I'd rather avoid the extra work. Thank you.
Nigella's Figs In Rum Syrup (from [HOW TO BE A DOMESTIC GODDESS](/books/how-to-be-a domestic-goddess)) are fresh figs that are cooked in a sugar syrup before they are transferred to steilized jars. It is not uncommon for sugar syrups to crystallize and it usually happens if the sugar is not completely dissolved before the syrup is brought to a boil. Any undissolved sugar crystals act as a "seed" and will draw molecules of sugar toward them as the syrup stands, eventually forming bigger crystals. Quite often there are small crystals of sugar clinging to the side of the saucepan, so use a clean pastry brush dipped in water to dissolve any sugar crystals on the side of the pan before bringing the syrup to a boil.
The density (concentration) of the syrup can also be a factor that affects crystals forming and this will vary according to the size of the pan, the amount of water that evaporates and the amount of rum added. The crystals are harmless and, as mentioned, can be dissolved again by warming the syrup. However adding an invert sugar to the syrup can also reduce the risk of crystals forming. Invert sugars include golden syrup, liquid glucose, agave syrup and corn syrup (use the light versions of agave and corn syrups). A mild liquid honey could also be used but avoid strongly flavoured honey and maple syrup as they could affect the flavour of the syrup. We would suggest adding 2 tablespoons of the invert sugar syrup to the sugar and water as you dissolve the sugar in the second step.